Method and apparatus to detect configuration information for a digital subscriber line device

ABSTRACT

A method and apparatus to detect configuration information that may be used to configure a permanent virtual circuit (PVC) between a digital subscriber line (DSL) customer premise equipment (CPE) and a DSL access module (DSLAM) is described.

BACKGROUND

[0001] As reliance on network communications increases, so does thedesire for high-speed network access. One popular technique forproviding high-speed network access is digital subscriber line (DSL)technology. DSL technology may be implemented with reducedinfrastructure costs through the use of conventional twisted-pair copperwires, which are already present in many homes and offices. As a resultof the many advantages offered by DSL technology, there may be asubstantial need for new and improved DSL technologies to furtherenhance these advantages while overcoming conventional limitations.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] The subject matter regarded as embodiments of the invention isparticularly pointed out and distinctly claimed in the concludingportion of the specification. Embodiments of the invention, however,both as to organization and method of operation, together with objects,features, and advantages thereof, may best be understood by reference tothe following detailed description when read with the accompanyingdrawings in which:

[0003]FIG. 1 is a system suitable for practicing one embodiment of theinvention.

[0004]FIG. 2 is a block diagram of a probing module in accordance withone embodiment of the invention.

[0005]FIG. 3 is a first block flow diagram of the programming logic thatmay be performed by a probing module in accordance with one embodimentof the invention.

[0006]FIG. 4 is a second block flow diagram of programming logic thatmay be performed by a probing module in accordance with one embodimentof the invention.

[0007]FIG. 5 is a third block flow diagram of programming logic that maybe performed by a probing module in accordance with one embodiment ofthe invention.

[0008]FIG. 6 is a fourth block flow diagram of programming logic thatmay be performed by a probing module in accordance with one embodimentof the invention.

DETAILED DESCRIPTION

[0009] Embodiments of the invention may comprise a method and apparatusto automatically detect configuration information for a DSL device. Forexample, the embodiments of the invention may automatically detectconfiguration information that may be used to configure a permanentvirtual circuit (PVC) between a DSL customer premise equipment (CPE) anda DSL access module (DSLAM). This may be advantageous, for example, whendifferent providers produce the DSL CPE and DSLAM. In this situation,the DSL CPE and DSLAM may not share the same PVC configurationinformation. Conventional techniques to handle this mismatch areunsatisfactory for a number of reasons, as detailed further below.

[0010] In this detailed description, numerous specific details are setforth in order to provide a thorough understanding of the embodiments ofthe invention. It will be understood by those skilled in the art,however, that the embodiments of the invention may be practiced withoutthese specific details. In other instances, well-known methods,procedures, components and circuits have not been described in detail soas not to obscure the embodiments of the invention. It can beappreciated that the specific structural and functional detailsdisclosed herein may be representative and do not necessarily limit thescope of the invention.

[0011] An embodiment of the invention may include functionality that maybe implemented as software executed by a processor, hardware circuits orstructures, or a combination of both. The processor may be ageneral-purpose or dedicated processor, such as a processor from thefamily of processors made by Intel Corporation, Motorola Incorporated,Sun Microsystems Incorporated and others. The software may compriseprogramming logic, instructions or data to implement certainfunctionality for an embodiment of the invention. The software may bestored in a medium accessible by a machine or computer-readable medium,such as read-only memory (ROM), random-access memory (RAM), magneticdisk (e.g., floppy disk and hard drive), optical disk (e.g., CD-ROM) orany other data storage medium. In one embodiment of the invention, themedia may store programming instructions in a compressed and/orencrypted format, as well as instructions that may have to be compiledor installed by an installer before being executed by the processor.Alternatively, an embodiment of the invention may be implemented asspecific hardware components that contain hard-wired logic forperforming the recited functionality, or by any combination ofprogrammed general-purpose computer components and custom hardwarecomponents.

[0012] It is worthy to note that any reference in the specification to“one embodiment” or “an embodiment” means that a particular feature,structure, or characteristic described in connection with the embodimentis included in at least one embodiment of the invention. The appearancesof the phrase “in one embodiment” in various places in the specificationare not necessarily all referring to the same embodiment.

[0013] Referring now in detail to the drawings wherein like parts aredesignated by like reference numerals throughout, there is illustratedin FIG. 1 a system suitable for practicing one embodiment of theinvention. FIG. 1 is a block diagram of a system 100 comprising a CPE102 connected to a DSLAM 106 via connection 104. DSLAM 106 may beconnected to a network device, such as router 110 via connection 108.CPE refers to a device located at a client or customer location, whichmay comprise hardware and/or software to communicate over a network toanother device. Examples of CPE may include a DSL or asymmetric DSL(ADSL) router, a DSL or ADSL bridge, a DSL or ADSL modem, and so forth.The term “CPE” as used herein may refer to both CPE and DSL CPE. In oneembodiment of the invention, CPE 102 may comprise a DSL CPE. The termDSL CPE as used herein may refer to any DSL device that is located at acustomer or client location. DSLAM 106 may be located, for example, at atelephone central office (TELCO).

[0014] A user may establish a DSL connection between CPE 102 and DSLAM106 using a number of well-known protocols, such as a High-level DataLink Control (HDLC), International Organization for Standardization,ISO/IEC 3309, adopted in 1993, Asynchronous Transfer Mode (ATM) layerspecification, International Telecommunication Union (ITU)Recommendation I.361, adopted in February 1999 (“ATM Specification”),Asynchronous Transfer Mode Forum and Frame-based User-Network Interface(ATM FUNI), The ATM Forum Technical Committee, defined in Frame BasedUser-To-Network Interface Specification v2.0, AF-SAA-0088.000, July1997. DSL CPE and DSLAMS are typically configured to communicate usingone or more such protocols.

[0015] The ATM protocol as described in the ATM Specification isbecoming increasingly popular for use in high-speed networks,particularly as used in combination with DSL technology. ATM is aconnection-orientated protocol and as such there is a connectionidentifier in every cell header that explicitly associates a cell with agiven virtual channel on a physical link. The connection identifier mayconsist of two sub-fields, the virtual channel identifier (VCI) and thevirtual path identifier (VPI). Together, the VCI and VPI are used inmultiplexing, de-multiplexing and switching a cell through the network.VCIs and VPIs are not necessarily addresses. They may be explicitlyassigned at each segment (link between ATM nodes) of a connection when aconnection is established, and remain for the duration of theconnection. Using the VCI/VPI the ATM layer can asynchronouslyinterleave (multiplex) cells from multiple connections.

[0016] An ATM connection may be of two types, often referred to as apermanent virtual circuit (PVC) and a switched virtual circuit (SVC). ASVC may be a temporary virtual circuit that is set up and used only aslong as data is being transmitted. Once the communication between thetwo hosts is complete, the SVC disappears. By way of contrast, a PVCremains available at all times.

[0017] During the initial deployment of a CPE 102, it may be desirableto configure a PVC between CPE 102 and DSLAM 106. Certain configurationinformation may be needed to configure the PVC between CPE 102 and DSLAM106. The configuration information may comprise, for example, a VCI andVPI as described above.

[0018] As mentioned previously, a problem may arise due to a mismatch inconfiguration information provisioned in the CPE and DSLAM. Frequently,the CPE and DSLAM are made by different vendors, and therefore do notprovision their equipment with the same configuration information. Forexample, the VCI and VPI values stored in the CPE may not be the sameVCI and VPI values stored in the DSLAM. As a result, when a new CPE isdeployed at a user location, a PVC between the CPE and DSLAM may not beconfigured absent some external mechanism. For example, a user may haveto manually enter the configuration information for the CPE, which mayoften be a tedious and time-consuming process, particularly with a largenumber of CPE deployments.

[0019] Another attempt to handle this mismatch is to automaticallyconfigure (auto-configure) a PVC. The term “automatically configure,”“auto-configure,” and its variants may be defined herein to meanconfiguration of a PVC with limited human intervention. A number of PVCautomated configuration solutions currently exist, such as thosedescribed in the DSL Forum PVC Auto-Configuration StandardSpecification, TR-037, the ATM Forum Integrated Local ManagementInterface (ILMI) Specification, AF-ILMI-0065, the ATM Forum PVCAuto-Configuration Specification, AF-NM-0122. Another technique referredto as “PVC Hunting” may also be used to automatically configure a PVC.PVC Hunting entails having the CPE passively listen to the received cellstream and determine an active PVC and associated configurationinformation from good cell headers.

[0020] The embodiments of the invention may comprise a new PVCauto-configuration algorithm that may be used to detect configurationinformation for a CPE. In one embodiment of the invention, this may beaccomplished using a list of probe values (“VC Table”). The term “probevalues” as used herein may refer to values for a virtual circuit, suchas a PVC. The values may comprise, for example, a VCI and VPI. Testpackets may be sent using the probe values to a DSLAM. The term “testpackets” as used herein may include packets designed specifically fortesting purposes, and also packets sent between a CPE and DSLAM inaccordance with normal data flow, such as for a conventional protocol.The DSLAM may reject or drop packets with unknown PVC values. If theDSLAM receives a packet with recognized PVC values, the DSLAM may send aresponse packet to the originating CPE. Alternatively, the DSLAM maypass the test packet to another network device attached to the samenetwork as the DSLAM and CPE, and the network device may send a responsepacket to the originating CPE. Examples of such network devices mightinclude a router, bridge, gateway, switch and so forth. Once theresponse packet is received, the CPE may retrieve the PVC configurationinformation from the header of the response packet. The CPE may thenconfigure the PVC using the retrieved configuration information.

[0021]FIG. 2 is a block diagram of a probing module in accordance withone embodiment of the invention. FIG. 2 illustrates a probing module 200that may be implemented as part of, for example, CPE 102. Probing module200 may include an event management module 202, a detection module 204,an extraction module 206 and a configuration module 208. As statedpreviously, each of these modules may be implemented in software,hardware or a combination of both. Further, it can be appreciated thatthe functionality for probing module 200 may be implemented using moremodules, or by combining these modules into fewer modules, and stillfall within the scope of the invention.

[0022] During an initialization or start-up process for a CPE such asCPE 102, it may be determined that a PVC is desired to communicate witha DSLAM, such as DSLAM 106. To accomplish this, event management module202 of probing module 200 may access a VC Table. The VC Table mayinclude a list of probe values. In one embodiment of the invention theprobes values may be, for example, a VCI and/or VPI. Event managementmodule 202 may use the VC Table to send test packets with differentprobe values to a DSLAM, such as DSLAM 106. Detection module 204 maydetect a response packet to one or more of the test packets. Theresponse packet may originate, for example, from DSLAM 106 or Router110. The response packet may also include a header having configurationinformation for a PVC. Extraction module 206 may extract theconfiguration information from the response packet, and pass theconfiguration information to configuration module 208. Configurationmodule 208 may use the configuration information to configure the PVCbetween the CPE and DSLAM.

[0023] The operations of systems 100 and 200 may be further describedwith reference to FIGS. 3-6 and accompanying examples. Although FIGS.3-6 presented herein may include a particular processing logic, it canbe appreciated that the processing logic merely provides an example ofhow the general functionality described herein can be implemented.Further, each operation within a given processing logic does notnecessarily have to be executed in the order presented unless otherwiseindicated. In one embodiment of the invention, the programming logic ofFIGS. 3-6 may be implemented using a processor and appropriate softwarecomprising computer program segments.

[0024]FIG. 3 is a first block flow diagram of the programming logic thatmay be performed by a probing module in accordance with one embodimentof the invention. In one embodiment of the invention, the probing modulemay refer to the software and/or hardware used to implement thefunctionality for PVC auto-configuration as described herein. In thisembodiment of the invention, the probing module may be implemented aspart of CPE 102. It can be appreciated that this functionality, however,may be implemented by any device, or combination of devices, locatedanywhere in a communication network accessible by CPE 102 and DSLAM 106and still fall within the scope of the invention.

[0025]FIG. 3 illustrates a programming logic 300 to configure a networkdevice, such as a DSL CPE. A request to configure a first PVC between aDSL device and a DSLAM is received at block 302. The first PVC isautomatically config ured using a list of probe values stored as part ofthe VC Table at block 304. An example of a VC Table is shown below asTable 1. TABLE 1 Probe Value Index VPI (N) VCI (M) Probe Value [0, 0] 035 Probe Value [1, 1] 0 32 Probe Value [N, M] 1 1

[0026] As shown in Table 1, a probe value may comprise a VPI and a VCI.Different CPE vendors may use different VPI and VCI values. For example,Probe Value [0, 0] may include a VPI=0 and a VCI=35. This is the defaultvalues used with CPE equipment provided by Alcatel. In another example,Probe Value [1, 1] may include a VPI=0 and a VCI=32, which are thedefault values used with CPE equipment provided by Siemens AG. In yetanother example, Probe Value [N, M] may include a VPI=1 and a VCI=1,which are the default values used with CPE equipment provided by CiscoSystems, Inc. A DSLAM, such as DSLAM 106, however, may not beprovisioned with these default values, therefore creating a potentialmismatch during the automatic configuration of a PVC between a CPE andDSLAM.

[0027]FIG. 4 is a second block flow diagram of programming logic thatmay be performed by a probing module in accordance with one embodimentof the invention. FIG. 4 illustrates a programming logic 400.Programming logic 400 is an example of how the first PVC may beautomatically configured. Test packets may be sent to a DSLAM, with eachtest packet having a probe value from the VC Table, at block 402. Aresponse packet to one of the test packets may be received at block 404.Configuration information may be retrieved from the response packet atblock 406. The PVC may be configured using the retrieved configurationinformation.

[0028]FIG. 5 is a third block flow diagram of programming logic that maybe performed by a probing module in accordance with one embodiment ofthe invention. FIG. 5 illustrates a programming logic 500. Programminglogic 500 is an example of test packets may be sent by, for example, aprobing module such as probing module 200. A probe value may beretrieved from a list of probe values stored in the VC Table at block502. In one embodiment of the invention the probe value may represent avirtual circuit as identified by a VPI and/or VCI. The virtual circuitmay be enabled at block 504. Once enabled, a test packet may be sentover the virtual circuit at block 506.

[0029] In one embodiment of the invention, a response packet mayindicate which virtual circuit is appropriate for use as a PVC.Therefore, those virtual circuits that were enabled but did not receivea response packet may be disabled, thereby releasing resources that maybe used for other connections.

[0030] In one embodiment of the invention, a CPE may use more than onePVC. In this case, configuration module 208 of probing module 200 may beused to configure multiple PVCs for the CPE. To configure multiple PVCsbetween a CPE and DSLAM, the configuration module may need additionalinformation from a user of the CPE. The configuration module maytherefore also include a user interface to allow a user to accesscertain functionality for the probing module in general and theconfiguration module in particular, such as providing configurationinformation for one or more PVCs, modifying time out periods for the PVCauto-configuration process, disabling certain PVC auto-configurationfunctions, and so forth.

[0031] One embodiment of invention may be used to configure a second PVCas follows. A request to configure a second PVC for said DSL device maybe received, along with configuration information for the second PVC.The configuration information may comprise, for example, a VCI and aVPI. The configuration module may then complete the configurationprocess for the second PVC using the configuration information.

[0032] In one embodiment of the invention, a terminating condition mayoccur prior to completing configuration of the first PVC. In this case,the first PVC may be manually configured. For example, a notice messageindicating that the first PVC was not configured may be sent to a user.Configuration information for the first PVC may be received from theuser via the user interface.

[0033]FIG. 6 is a fourth block flow diagram of programming logic thatmay be performed by a probing module in accordance with one embodimentof the invention. FIG. 6 illustrates a programming logic 600.Programming logic 600 begins by waiting for a detection start request atblock 602. Block 602 may be an idle state waiting to receive a requestto being probing for configuration information. A detection startrequest may be received at block 604. The detection start request mayoriginate from a initialization sub-routine that is executed, forexample, upon start-up of a CPE. Once the detection start request isreceived, the probing module may begin the probing and configurationprocess by enabling transmit (Tx) and receive (Rx) functions for allvirtual circuits as represented by probe values in the VC Table at block606.

[0034] Programming logic 600 may invoke a monitoring sub-routine atblock 608. The monitoring sub-routine may wait for a predefined event,such as receipt of a response packet or configuration packet from aDSLAM, for example. A determination is made at block 610 as to whetheran event has been detected. If no events have been detected, a requestto send test packets may be sent to block 612. The test packets may be,for example, ATM adaptation layer (AAL) protocol data units (PDUs).Block 612 may initiate the broadcasting of transmit AAL PDUs to theDSLAM on all virtual circuits as represented by probe values stored aspart of the VC Table. In the event of a terminating condition, such as atime-out, a detection reset request may be forwarded to block 602 atblock 610.

[0035] The test packets may be received by the DSLAM. The DSLAM maydiscard any invalid test packets, such as those test packets received onunknown virtual circuits. The DSLAM may then forward the test packet toanother network device on the configured virtual circuit. The networkdevice may be part of the backbone network, such as router 110, forexample. The router 110 on the backbone network may respond to the testpacket in the form of an AAL PDU, and the response may be forwarded tothe DSLAM, and from the DSLAM to the CPE on the configured virtualcircuit. The CPE may now be able to detect the configured virtualcircuit through the received AAL PDU. Alternatively, the DSLAM may sendthe response packet to the originating CPE without passing it to anothernetwork device.

[0036] Once the test packets or PDUs are sent to the DSLAM at block 612,the monitoring sub-routine at block 608 may wait for a predefined event,such as receipt of a response packet to one of the test packets. Themonitoring sub-routine may listen for received AAL PDUs on the same listof virtual circuits used to send the test packets. A determination ismade at block 610 as to whether a response packet has been received. Ifa response packet has been received, a message is passed to block 614that a response packet has been received, and the virtual circuit overwhich it was received. The response packet or PDU is forwarded toanother sub-routine on a different networking layer, and may be used tovalidate and store configuration information to establish a PVC for theCPE. The detecting process may be terminated at block 616. The Tx and RXfunctions for all virtual circuits that did not receive a responsepacket may also be disabled or turned off at block 616. Finally, amessage may be sent to permanently enable the virtual circuit (VCx) thatreceived a response packet at block 616, and control may be passed toblock 602 for the next detection start request.

[0037] The operation of systems 100 and 200, and the processing logicshown in FIGS. 3-6 may be better understood by way of example. Assume aCPE is scheduled for deployment. The CPE may be, for example, a CPE todeliver ATM over DSL, such as a DSL/ATM router, an ADSL/ATM router, aDSL/ATM bridge, an ADSL/ATM bridge, a DSL or ADSL modem, and so forth.The DSL CPE is connected to a TELCO DSLAM over a communications medium,such as twisted-pair copper wire. Power is delivered to the DSL CPE, andan initialization routine is started. Part of the initialization routinemay be to detect whether a PVC has been configured for the DSL CPE. Ifthere is no PVC configured for the DSL CPE, a request to configure a PVCbetween the DSL CPE and the DSLAM is sent to probing module 200. Uponreceiving the configuration request, event management module 202 ofprobing module 200 may access probe values stored in a VC Table, such asthe VC Table illustrated as Table 1. Event management module 202 mayenable virtual circuits represented by the probe values, and beginsending test packets to the DSLAM using the probe values. For example,probe value [1, 1] would be used to construct a virtual circuit, withthe virtual circuit being identified with a VPI of 0 and a VCI of 35.

[0038] Detection module 204 may remain in an idle state and monitor forresponse packet(s) from the DSLAM or some other network device (e.g.,router 100). Once a response packet is received, detection module 204may notify extraction module 206 of the response packet. Detectionmodule 204 may perform some clean-up operations as well, such asshutting down or disabling those virtual circuits that did not receive aresponse packet. For example, if a response packet was received over thevirtual circuit having a VPI of 0 and VCI of 35, all other virtualcircuits may be disable to release resources for other connections.

[0039] Extraction module 206 may be used to extract configurationinformation resulting from receipt of a response packet. Theconfiguration information may be extracted, for example, from a cellheader from the response packet. The configuration information may alsobe retrieved using the probe values that were used to enable the virtualcircuit that received the response packet. Extraction module 206 mayalso validate that the virtual circuit is a valid virtual circuit bysending additional test packets, of the same kind sent initially or ofdifferent types to further test the connection.

[0040] Once validated, configuration module 208 may store theconfiguration information, and permanently activate and identify thevirtual circuit identified by the configuration information as the PVCbetween the CPE and DSLAM. Configuration module 208 may then send amessage to a user indicating configuration is complete for the PVC. Itis worthy to note that the probing process may be executed during othertimes in addition to CPE initialization and still fall within the scopeof the invention. For example, the probing process may be used to set upa PVC for a particular session, or upon delivery of power to the CPE.The probing process may also be performed once, with the PVCconfiguration information being stored for subsequent sessions.

[0041] In one embodiment of the invention, a terminating condition mayoccur prior to completing configuration of the PVC. In this case, thePVC may be manually configured. For example, a notice message indicatingthat the PVC was not configured may be sent to a user. Configurationinformation for the PVC may be received from the user via the userinterface. Configuration module 208 may use the configurationinformation to complete the PVC configuration process.

[0042] In some cases the DSL CPE will use multiple PVCs. In this case,the probing module may configure multiple PVCs for the CPE. This may beaccomplished by having configuration information for the additional PVCsmanually configured using, for example, the user interface. For example,configuration module 208 may receive a request to configure a second PVCfor the DSL device, along with configuration information for the secondPVC. Upon detection of configuration information included as part of theconfiguration request, configuration module 208 may store theconfiguration information and active the second PVC. A PVC configurationcomplete message may then be sent to the user. This process may berepeated for any number of PVCs desired for a particular DSL CPE.

[0043] Broadcasting test packets may introduce additional load on acommunication line or network, and there may be a practical upper limiton the number of active virtual circuit probes that may be handled bythe network. During actual detection, the traffic may be limited sincethere are no logical connections established at this stage. In oneembodiment of the invention, the load in the transmit direction may becontrolled by conventional high water marks on the transmission queues,for example.

[0044] While certain features of the embodiments of the invention havebeen illustrated as described herein, many modifications, substitutions,changes and equivalents will now occur to those skilled in the art. Itis, therefore, to be understood that the appended claims are intended tocover all such modifications and changes as fall within the true spiritof the embodiments of the invention.

1. A method to configure a network device, comprising: receiving arequest to configure a first permanent virtual circuit (PVC) between adigital subscriber line (DSL) device and a DSL access module (DSLAM);and automatically configuring said first PVC using a list of probevalues to probe for configuration information for said PVC, and usingsaid configuration information to configure said first PVC.
 2. Themethod of claim 1, wherein said automatically configuring comprises:sending test packets to said DSLAM using said probe values; receiving aresponse packet to one of said test packets; retrieving saidconfiguration information from said response packet; and configuringsaid PVC using said retrieved configuration information.
 3. The methodof claim 2, wherein for each probe value in said probe table saidsending comprises: retrieving a probe value from said list of probevalues, wherein said probe value represents a virtual circuit; enablingsaid virtual circuit; and sending a test packet over said virtualcircuit.
 4. The method of claim 3, further comprising disabling eachvirtual circuit that did not receive a response packet.
 5. The method ofclaim 1, further comprising: receiving a request to configure a secondPVC for said DSL device; receiving configuration information for saidsecond PVC; and configuring said second PVC using said configurationinformation.
 6. The method of claim 1, wherein said configurationinformation may comprise a virtual channel identifier (VCI) and avirtual path identifier (VPI).
 7. The method of claim 1, furthercomprising: determining that a terminating condition has occurred priorto automatically configuring said first PVC; sending a message that saidfirst PVC was not configured to a user; and receiving said configurationinformation for said first PVC from a user.
 8. A system to configure anetwork device, comprising: a digital subscriber line (DSL) customerpremise equipment (CPE); a DSL access module (DSLAM) connected to saidDSL CPE; and a DSL probing module to use probe values to detectconfiguration information for use in configuring a permanent virtualcircuit (PVC) between said DSL CPE and said DSLAM.
 9. The system ofclaim 8, wherein said DSL CPE comprises a DSL CPE consisting essentiallyone of the following: a DSL/asynchronous transfer mode (ATM) router, anasymmetric DSL (ADSL)/ATM router, a DSL/ATM bridge, an ADSL/ATM bridge,a DSL modem, and an ADSL modem.
 10. The system of claim 8, wherein saidPVC may be configured using configuration information comprising avirtual channel identifier (VCI) and a virtual path identifier (VPI).11. A probing module for a network device, comprising: an eventmanagement module to send test packets using probe values from a digitalsubscriber line (DSL) device to a DSL access module (DSLAM); a detectionmodule to detect a packet received in response to at least one of saidtest packets; and an extraction module to retrieve configurationinformation from said received packet.
 12. The probing module of claim11, further comprising a configuration module to configure a permanentvirtual connection between said DSL and said DSLAM using s aidconfiguration information.
 13. The probing module of claim 11, whereinsaid configuration information may comprise a virtual channel identifier(VCI) and a virtual path identifier (VPI).
 14. An article comprising: astorage medium; said storage medium including stored instructions that,when executed by a processor, result in configuring a network device byreceiving a request to configure a first permanent virtual circuit (PVC)between a digital subscriber line (DSL) device and a DSL access module(DSLAM), and automatically configuring said first PVC using alist ofprobe values to probe for configuration information for said PVC, andusing said configuration information to configure said first PVC. 15.The article of claim 14, wherein the stored instructions, when executedby a processor, result in automatically configuring said first PVC bysending test packets to said DSLAM using said probe values, receiving aresponse packet to one of said test packets, retrieving saidconfiguration information from said response packet, and configuringsaid PVC using said retrieved configuration information.
 16. The articleof claim 15, wherein the stored instructions, when executed by aprocessor, result in sending test packets, for each probe value in saidprobe table, by retrieving a probe value from said list of probe values,wherein said probe value represents a virtual circuit, enabling saidvirtual circuit, and sending a test packet over said virtual circuit.17. The article of claim 16, wherein the stored instructions, whenexecuted by a processor, further result in disabling each virtualcircuit that did not receive a response packet.
 18. The article of claim14, wherein the stored instructions, when executed by a processor,further result in receiving a request to configure a second PVC for saidDSL device, receiving configuration information for said second PVC, andconfiguring said second PVC using said configuration information. 19.The article of claim 14, wherein the stored instructions, when executedby a processor, further result in determining that a terminatingcondition has occurred prior to automatically configuring said firstPVC, sending a message that said first PVC was not configured to a user,and receiving said configuration information for said first PVC from auser.